Classifications of Intentions for Controlling of a Multifunctional Knee-Ankle-Foot Orthosis

2011 ◽  
Author(s):  
Sai-Kit Wu ◽  
Tad Driver ◽  
Xiangrong Shen
Keyword(s):  
Walking Speed ◽  
Accuracy Rate ◽  
Bayes Method ◽  
Ankle Foot Orthosis ◽  
Significant Step ◽  
Reaction Forces ◽  
Velocity Information ◽  
Foot Orthosis ◽  
Motion Intention

This paper describes motion intention classifiers which utilize reaction forces signals from heel and toe; and hip velocity information to predict subject’s intention. Those classifiers using Bayes method to predict (i) walk-to-stop, (ii) walking-speed-changing, and (iii) stop-to-motions. They are very accurate (most of them have accuracy rate higher than 90%) and a significant step in order to develop a multifunctional knee-ankle-foot orthosis.

scholarly journals Effectiveness of an ankle–foot orthosis on walking in patients with stroke: a systematic review and meta-analysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yoo Jin Choo ◽  
Min Cheol Chang
Keyword(s):  
Stride Length ◽  
Walking Speed ◽  
Sagittal Plane ◽  
Meta Analysis ◽  
Step Length ◽  
Stride Time ◽  
Plane Angle ◽  
Ankle Foot Orthosis ◽  
Biomechanical Parameters ◽  
Foot Orthosis

AbstractWe conducted a meta-analysis to investigate the effectiveness of ankle–foot orthosis (AFO) use in improving gait biomechanical parameters such as walking speed, mobility, and kinematics in patients with stroke with gait disturbance. We searched the MEDLINE (Medical Literature Analysis and Retrieval System Online), CINAHL (Cumulative Index to Nursing and Allied Health Literature), Cochrane, Embase, and Scopus databases and retrieved studies published until June 2021. Experimental and prospective studies were included that evaluated biomechanics or kinematic parameters with or without AFO in patients with stroke. We analyzed gait biomechanical parameters, including walking speed, mobility, balance, and kinematic variables, in studies involving patients with and without AFO use. The criteria of the Cochrane Handbook for Systematic Reviews of Interventions were used to evaluate the methodological quality of the studies, and the level of evidence was evaluated using the Research Pyramid model. Funnel plot analysis and Egger’s test were performed to confirm publication bias. A total of 19 studies including 434 participants that reported on the immediate or short-term effectiveness of AFO use were included in the analysis. Significant improvements in walking speed (standardized mean difference [SMD], 0.50; 95% CI 0.34–0.66; P < 0.00001; I2, 0%), cadence (SMD, 0.42; 95% CI 0.22–0.62; P < 0.0001; I2, 0%), step length (SMD, 0.41; 95% CI 0.18–0.63; P = 0.0003; I2, 2%), stride length (SMD, 0.43; 95% CI 0.15–0.71; P = 0.003; I2, 7%), Timed up-and-go test (SMD, − 0.30; 95% CI − 0.54 to − 0.07; P = 0.01; I2, 0%), functional ambulation category (FAC) score (SMD, 1.61; 95% CI 1.19–2.02; P < 0.00001; I2, 0%), ankle sagittal plane angle at initial contact (SMD, 0.66; 95% CI 0.34–0.98; P < 0.0001; I2, 0%), and knee sagittal plane angle at toe-off (SMD, 0.39; 95% CI 0.04–0.73; P = 0.03; I2, 46%) were observed when the patients wore AFOs. Stride time, body sway, and hip sagittal plane angle at toe-off were not significantly improved (p = 0.74, p = 0.07, p = 0.07, respectively). Among these results, the FAC score showed the most significant improvement, and stride time showed the lowest improvement. AFO improves walking speed, cadence, step length, and stride length, particularly in patients with stroke. AFO is considered beneficial in enhancing gait stability and ambulatory ability.

scholarly journals The physiological cost index of walking with a powered knee–ankle–foot orthosis in subjects with poliomyelitis: A pilot study

2015 ◽  
Vol 40 (4) ◽  
pp. 454-459 ◽  
Author(s):  
Mokhtar Arazpour ◽  
Monireh Ahmadi Bani ◽  
Mohammad Samadian ◽  
Mohammad E Mousavi ◽  
Stephen W Hutchins ◽  
...  
Keyword(s):  
Walking Speed ◽  
Knee Joints ◽  
Cost Index ◽  
Ankle Foot Orthosis ◽  
Physiological Cost ◽  
Active Flexion ◽  
Quasi Experimental ◽  
Locked Knee ◽  
Foot Orthosis ◽  
Flexion And Extension

Background: A powered knee–ankle–foot orthosis was developed to provide restriction of knee flexion during stance phase and active flexion and extension of the knee during swing phase of gait. Objective: The purpose of this study was to determine its effect on the physiological cost index, walking speed and the distance walked in people with poliomyelitis compared to when walking with a knee–ankle–foot orthosis with drop lock knee joints. Study design: Quasi experimental study. Methods: Seven subjects with poliomyelitis volunteered for the study and undertook gait analysis with both types of knee–ankle–foot orthosis. Results: Walking with the powered knee–ankle–foot orthosis significantly reduced walking speed ( p = 0.015) and the distance walked ( p = 0.004), and also, it did not improve physiological cost index values ( p = 0.009) compared to walking with the locked knee–ankle–foot orthosis. Conclusion: Using a powered knee–ankle–foot orthosis did not significantly improve any of the primary outcome measures during walking for poliomyelitis subjects. Clinical relevance This powered knee–ankle–foot orthosis design did not improve the physiological cost index of walking for people with poliomyelitis when compared to walking with a knee–ankle–foot orthosis with drop lock knee joints. This may have been due to the short training period used or the bulky design and additional weight of the powered orthosis. Further research is therefore warranted.

scholarly journals Control Reference Parameter for Stance Assistance Using a Passive Controlled Ankle Foot Orthosis—A Preliminary Study

2019 ◽  
Vol 9 (20) ◽  
pp. 4416 ◽  
Author(s):  
Dimas Adiputra ◽  
Mohd Azizi Abdul Rahman ◽  
Ubaidillah ◽  
Saiful Amri Mazlan ◽  
Nurhazimah Nazmi ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
Standard Error ◽  
Walking Speed ◽  
Parameters Estimation ◽  
Ankle Foot Orthosis ◽  
Preliminary Study ◽  
Reference Parameters ◽  
Walking Speeds ◽  
Foot Orthosis

This paper aims to present a preliminary study of control reference parameters for stance assistance among different subjects and walking speeds using a passive-controlled ankle foot orthosis. Four young male able-bodied subjects with varying body mass indexes (23.842 ± 4.827) walked in three walking speeds of 1, 3, and 5 km/h. Two control references, average ankle torque (aMa), and ankle angular velocity (aω), which can be implemented using a magnetorheological brake, were measured. Regression analysis was conducted to identify suitable control references in the three different phases of the stance. The results showed that aω has greater correlation (p) with body mass index and walking speed compared to aMa in the whole stance phase (p1(aω) = 0.666 > p1(aMa) = 0.560, p2(aω) = 0.837 > p2(aMa) = 0.277, and p3(aω) = 0.839 > p3(aMa) = 0.369). The estimation standard error (Se) of the aMa was found to be generally higher than of aω (Se1(aMa) = 2.251 > Se1(aω) = 0.786, Se2(aMa) = 1.236 > Se2(aω) = 0.231, Se3(aMa) = 0.696 < Se3(aω) = 0.755). Future studies should perform aω estimation based on body mass index and walking speed, as suggested by the higher correlation and lower standard error as compared to aMa. The number of subjects and walking speed scenarios should also be increased to reduce the standard error of control reference parameters estimation.

The effect of a knee ankle foot orthosis incorporating an active knee mechanism on gait of a person with poliomyelitis

2013 ◽  
Vol 37 (5) ◽  
pp. 411-414 ◽  
Author(s):  
Mokhtar Arazpour ◽  
Ahmad Chitsazan ◽  
Monireh Ahmadi Bani ◽  
Gholamreza Rouhi ◽  
Farhad Tabatabai Ghomshe ◽  
...  
Keyword(s):  
Knee Flexion ◽  
Walking Speed ◽  
Horizontal Displacement ◽  
Step Length ◽  
Knee Extension ◽  
Knee Joints ◽  
Ankle Foot Orthosis ◽  
Stance Control ◽  
Control Knee ◽  
Foot Orthosis

Background: The aim of this case study was to identify the effect of a powered stance control knee ankle foot orthosis on the kinematics and temporospatial parameters of walking by a person with poliomyelitis when compared to a knee ankle foot orthosis. Case description and methods: A knee ankle foot orthosis was initially manufactured by incorporating drop lock knee joints and custom molded ankle foot orthoses and fitted to a person with poliomyelitis. The orthosis was then adapted by adding electrically activated powered knee joints to provide knee extension torque during stance and also flexion torque in swing phase. Lower limb kinematic and kinetic data plus data for temporospatial parameters were acquired from three test walks using each orthosis. Findings and outcomes: Walking speed, step length, and vertical and horizontal displacement of the pelvis decreased when walking with the powered stance control knee ankle foot orthosis compared to the knee ankle foot orthosis. When using the powered stance control knee ankle foot orthosis, the knee flexion achieved during swing and also the overall pattern of walking more closely matched that of normal human walking. The reduced walking speed may have caused the smaller compensatory motions detected when the powered stance control knee ankle foot orthosis was used. Conclusion: The new powered SCKAFO facilitated controlled knee flexion and extension during ambulation for a volunteer poliomyelitis person. Clinical relevance The powered stance control knee ankle foot orthosis has the potential to improve knee joint kinematics in persons with poliomyelitis when ambulating.

scholarly journals A Model to Predict the Effect of Ankle Joint Misalignment on Calf Band Movement in Ankle-Foot Orthoses

2007 ◽  
Vol 31 (1) ◽  
pp. 76-87 ◽  
Author(s):  
Stefania Fatone ◽  
Andrew H. Hansen
Keyword(s):  
Ankle Joint ◽  
Walking Speed ◽  
Sagittal Plane ◽  
Plantar Flexion ◽  
Dimensional Model ◽  
Ankle Foot Orthosis ◽  
Ankle Joints ◽  
Ankle Foot Orthoses ◽  
Foot Orthosis ◽  
Anterior Posterior

Accurate alignment of anatomical and mechanical joint axes is one of the major biomechanical principles pertaining to articulated orthoses, yet knowledge of the potential effects of axis misalignment is limited. The purpose of this project was to model the effects of systematic linear (proximal-distal and anterior-posterior) misalignments of single axis mechanical ankle joints in an ankle-foot orthosis (AFO) in order to determine the degree and direction of calf band travel that would occur over a functional range of motion. Sagittal plane misalignments of the ankle joint centres of an AFO were simulated using a simple two-dimensional model for both a range of ankle angles and a typical able-bodied ankle kinematic curve for self-selected normal walking speed. The model assumed that no movement occurred between the foot and the foot-plate of the AFO. The model predicted that for anterior (positive horizontal) misalignments, dorsiflexion movements would cause the calf band to travel proximally (i.e., up the leg) and plantar flexion movements would cause the calf band to travel distally (i.e., down the leg). The opposite was predicted for posterior (negative horizontal) misalignments. Proximal (positive vertical) misalignments would cause only distal movements of the calf band while distal (negative vertical) misalignments would cause only proximal movements of the calf band. Anterior-posterior misalignments were found to have a much larger effect on the amount of calf band travel than proximal-distal misalignments.

scholarly journals The effect of different shoes on functional mobility and energy expenditure in post-stroke hemiplegic patients using ankle–foot orthosis

2016 ◽  
Vol 40 (5) ◽  
pp. 591-597 ◽  
Author(s):  
Farzad Farmani ◽  
Mohammad Ali Mohseni Bandpei ◽  
Mahmood Bahramizadeh ◽  
Gholamreza Aminian ◽  
Mohammad Reza Nikoo ◽  
...  
Keyword(s):  
Energy Expenditure ◽  
Walking Speed ◽  
Functional Mobility ◽  
Timed Up And Go ◽  
Ankle Foot Orthosis ◽  
Post Stroke ◽  
Group I ◽  
Ankle Foot Orthoses ◽  
Rocker Shoes ◽  
Foot Orthosis

Background:Ankle–foot orthoses could be utilized both with and without shoes. While several studies have shown that ankle–foot orthoses improve gait abilities in hemiplegic patients, it remains unclear whether they should be used with shoes or without.Objectives:The study purpose was to compare the effect of standard shoes and rocker shoes on functional mobility in post-stroke hemiplegic patients utilizing ankle–foot orthosis.Study design:Randomized clinical study.Methods:Thirty post-stroke hemiplegic patients participated in this study randomly assigned to two groups. Group I received standard shoes + ankle–foot orthosis and group II were provided with rocker shoes + ankle–foot orthosis. Their functional mobility and energy expenditure parameters including timed up and go, timed up stairs, timed down stairs, preferred walking speed, and oxygen (O2) cost (mL/kg/m) were measured.Results:In group I, no significant changes were seen in outcome measures after wearing standard shoes. While in group II, O2cost and timed up and go time significantly decreased, and preferred walking speed increased when patients wore rocker shoes. Also, there was a significant difference between rocker shoes and standard shoes in improvement of timed up and go, preferred walking speed, and O2cost.Conclusion:When patients using ankle–foot orthosis wore rocker shoes, their functional mobility improved and oxygen cost diminished. Also, rocker shoes was significantly more effective than standard shoes in improving functional mobility parameters.Clinical relevanceThis study suggests that in post-stroke hemiplegic patients using ankle–foot orthosis, wearing rocker shoes can lead to much more improved functional mobility and decreased energy expenditure compared to ankle–foot orthosis only. Thus, in stroke patients, the combination of ankle–foot orthosis-rocker shoes is recommended for both rehabilitation programs and ankle–foot orthosis efficacy investigations.

scholarly journals The Comparison of the Effects of Flexible vs Rigid Ankle-foot orthoses on Balance and Walking Performance in Individuals With Multiple Sclerosis: A Crossover Study

2021 ◽  
Vol 19 (2) ◽  
pp. 199-206
Author(s):  
Sama-Sadat Parian ◽  
◽  
Niloufar Fereshtenejad ◽  
Susan Hillier ◽  
Ebrahim Sadeghi-Demneh ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Crossover Study ◽  
Postural Stability ◽  
Walking Speed ◽  
Foot Orthoses ◽  
Timed Up And Go ◽  
Walking Test ◽  
Ankle Foot Orthosis ◽  
Ankle Foot Orthoses ◽  
Foot Orthosis

Objectives: Ankle-Foot orthoses are used to minimize the impact of weakness in ankle dorsiflexion muscles. The study on different orthotic types defines the optimal design, which effectively improves the users’ mobility. This study investigated the potential benefits and risks of a Dictus-band (flexible orthotic), compared with a thermoplastic (fixed) ankle-foot orthosis on the mobility of individuals with Multiple Sclerosis (MS). Methods: Fifteen subjects with MS and dorsiflexion ankle weakness volunteered in this randomized crossover study. The study participants received either a Dictus-band or a thermoplastic ankle-foot orthosis worn on the weaker leg, compared to barefoot as the control condition. Postural stability during standing, forward reach test, timed up and go test, and walking speed in the 10-meter walking test were compared between the study conditions. Results: There were no significant differences in the postural stability and forward reach tests between study conditions (P>0.5). When the research participants used a Dictus-band, compared to the fixed ankle-foot orthosis, the time required to complete the timed up and go was significantly reduced [P<0.01; Mean±SD difference: 6.4±1.4; 95% Confidence Interval (CI): 2.7-10.2], and walking speed was increased in the 10-meter walking test (P<0.01; Mean±SD difference: 0.46±0.8; 95%CI: 0.23-0.69). There was no difference in the timed up and go and 10-meter walking test data between the barefoot and Dictus-band conditions (P>0.5). No adverse or safety events were sustained in this research. Discussion: The present study data provided initial evidence for the lack of detrimental effects of using the Dictus-band in subjects with MS and ankle dorsiflexion deficiencies.

scholarly journals Change of rocker function in the gait of stroke patients using an ankle foot orthosis with an oil damper: immediate changes and the short-term effects

2011 ◽  
Vol 35 (4) ◽  
pp. 350-359 ◽  
Author(s):  
Sumiko Yamamoto ◽  
Masako Fuchi ◽  
Tadashi Yasui
Keyword(s):  
Ankle Joint ◽  
Walking Speed ◽  
Chronic Phase ◽  
Gait Training ◽  
Stroke Patients ◽  
Short Term ◽  
Ankle Foot Orthosis ◽  
Spatiotemporal Parameters ◽  
Foot Orthosis ◽  
Short Term Effects

Background: An ankle foot orthosis (AFO) using an oil damper (AFO-OD) to assist the first rocker during gait was previously developed but the effect on the other rocker functions has not been clarified. Objectives: The immediate and short-term effects on the gait of stroke patients with the AFO-OD were investigated from the viewpoint of the rocker function. Study Design: Crossover study. Methods: The gait of eight stroke patients in chronic phase without an AFO, with the AFO-OD, and the gait with AFO-OD after three weeks of continuous use and gait training were measured by 3D motion analysis. Results: Immediate changes observed on use of the AFO-OD were improvements in walking speed, the spatiotemporal parameters, and the angular change of dorsiflexion of the ankle joint. Three weeks of continuous AFO-OD use and gait training showed further improvements in walking speed and the spatiotemporal parameters as well as an increase in dorsiflexion angle and plantar flexor moment of the ankle joint of the paretic limb in stance. Conclusions: These changes produced improvement of the second rocker function, but improvement of the third rocker was insufficient. Results show the importance of gait training to take full advantage of an AFO.

A Novel Device to Evaluate the Stiffness of Ankle-Foot Orthosis Devices

2003 ◽  
Vol 125 (6) ◽  
pp. 913-917 ◽  
Author(s):  
P. Cappa, ◽  
F. Patane`, ◽  
M. M. Pierro
Keyword(s):  
Mechanical Behavior ◽  
Gait Analysis ◽  
Clinical Management ◽  
Testing Apparatus ◽  
Ankle Foot Orthosis ◽  
Novel Device ◽  
Reaction Forces ◽  
Global Accuracy ◽  
Foot Orthosis ◽  
Induced Reaction

The evaluation of mechanical behavior of plastic Ankle-Foot Orthosis (AFO) is important since AFO can provide an efficient support to patients with disabilities in locomotion. This paper reports on a novel testing apparatus that allows: (a) the evaluation of AFO stiffness in sagittal and frontal planes; (b) the conduction of semi-automatic trials; and, finally, (c) a global accuracy associated to the AFO stiffness values always less than 4%. The stiffness values are determined by the measurements of the imposed relative displacements between the foot and the shank of the orthosis and the induced reaction forces. The data collected together in an exact 2-D approach, together with those provided by gait analysis systems, allows to better understand gait alteration induced by ankle orthosis, and to improve clinical management of patients.

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